Undifferentiated chest pain in the young patient, pleuritic, MSK, anxiety, PE Wells score, conservative imaging

Definition / Overview

• Undifferentiated chest pain in young adults (typically defined as age <40 years) represents a common Emergency Department presentation that requires systematic clinical reasoning to distinguish benign self-limiting conditions from rare but life-threatening pathology.
• Unlike older adults where atherosclerotic coronary disease predominates, young patients present a broader differential spanning cardiac, pulmonary, musculoskeletal, gastrointestinal, and psychological aetiologies.
• The primary clinical challenge lies in balancing diagnostic thoroughness against unnecessary investigation and radiation exposure in a cohort where serious pathology is uncommon. Clinical Pearl: In Australian EDs, approximately 80-85% of chest pain in patients under 35 years has a benign cause, yet the medicolegal environment drives defensive imaging practices that expose young patients to cumulative radiation risk.
• This note focuses on structured assessment using validated clinical decision tools (Wells score for PE, PERC rule), rational D-dimer interpretation, and evidence-based conservative imaging philosophies aligned with current ACEM position statements and eTG Complete recommendations.

The approach must systematically exclude time-critical diagnoses (pulmonary embolism, aortic dissection, pneumothorax, myocarditis, spontaneous coronary artery dissection) while avoiding over-investigation of common presentations like costochondritis, anxiety, and gastro-oesophageal reflux disease.

Clinical Background

Epidemiology and Risk Stratification

• Young adults constitute approximately 15-20% of ED chest pain presentations across Australian tertiary centres.
• The pre-test probability for acute coronary syndrome is substantially lower than in older cohorts, but specific risk factors modify this baseline risk.
• Cocaine and methamphetamine use (particularly crystalline methamphetamine which has high prevalence in regional Australia) increase risk through coronary vasospasm and accelerated atherosclerosis.
• Familial hypercholesterolaemia affects 1 in 500 Australians and can cause premature coronary disease in the third decade.

Cardiac Causes in Young Adults

• Myocarditis typically follows viral upper respiratory infection (Coxsackie B, adenovirus, parvovirus B19) or occurs as post-viral inflammatory syndrome.
• Since 2021, Australian surveillance data (TGA and Department of Health) documented increased myocarditis/pericarditis cases following mRNA COVID-19 vaccination, predominantly in males aged 12-29 years after second doses, with incidence approximately 1-2 per 100,000 doses.
• Most cases are mild and self-limiting.
• Spontaneous coronary artery dissection (SCAD) predominantly affects women aged 30-50 years, often peripartum or in association with fibromuscular dysplasia.
• It accounts for up to 35% of acute MI in women under 50 years.
• Aortic dissection in young patients typically occurs with underlying connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome type IV, Loeys-Dietz syndrome, Turner syndrome) or bicuspid aortic valve.
• Family history of dissection or sudden death before age 50 years is critical. Red Flag: Tearing chest or interscapular pain with pulse differential between arms, blood pressure differential >20 mmHg, or new aortic regurgitation murmur mandates urgent CT aortogram.

Anomalous coronary arteries (particularly anomalous left coronary from right sinus with interarterial course) can cause exertional chest pain, syncope, or sudden cardiac death in adolescents and young adults during vigorous exercise.

Non-Cardiac Causes

Pulmonary embolism occurs in young patients with identifiable risk factors in approximately 75% of cases (oral contraceptive pill use, recent travel, pregnancy/postpartum, thrombophilia, malignancy, surgery). eTG Complete emphasises structured risk assessment using validated tools before imaging.

• Pneumothorax has bimodal distribution with primary spontaneous pneumothorax occurring in tall, thin males aged 20-30 years (often during minimal exertion or rest).
• Smoking increases risk 20-fold.
• Recurrence risk is 30% after first episode, 60% after second.
• Costochondritis (Tietze syndrome when associated with swelling) affects the costochondral or costosternal junctions, typically 2nd-5th ribs.
• Reproducible chest wall tenderness is highly sensitive but not specific.
• Anxiety and panic disorder cause chest tightness, dyspnoea, palpitations, and paraesthesias.
• Australian epidemiological data (ABS National Health Survey) indicate anxiety disorders affect 16% of adults aged 16-34 years, with peak onset in late adolescence and early twenties.
• Diagnosis requires exclusion of organic pathology and positive identification of anxiety symptoms.
• Gastro-oesophageal reflux disease (GORD) causes retrosternal burning pain, often worse lying flat or after meals.
• The "GI cocktail" (antacid with viscous lignocaine) historically used for diagnostic purposes has poor sensitivity and specificity and should not guide clinical decision-making.

Clinical Features

History

Systematic characterisation using SOCRATES framework: Site, Onset, Character, Radiation, Associations, Timing, Exacerbating/relieving factors, Severity.

Cardiac red flags: Exertional symptoms, radiation to jaw/arm, diaphoresis, nausea/vomiting, family history of premature CAD (<55 years males, <65 years females), known coronary risk factors, syncope.

PE features: Pleuritic pain (sharp, worse with inspiration), dyspnoea, haemoptysis, unilateral leg swelling, recent immobilisation, oestrogen therapy, known thrombophilia.

Pneumothorax features: Sudden-onset unilateral pleuritic pain with dyspnoea, typically at rest or minimal exertion in tall thin males or during diving/flying in those with underlying lung disease.

Musculoskeletal features: Reproducible positional chest wall tenderness, recent trauma or unusual physical activity, clear relationship to movement.

Anxiety features: Acute onset panic, hyperventilation, perioral and digital paraesthesias, sense of doom, previous similar episodes in stressful situations.

Examination

• Vital signs: Tachycardia and tachypnoea require explanation.
• Fever suggests infection (pleurisy, pneumonia, myocarditis). Clinical Pearl: Pulse oximetry is insensitive for PE; normal SpO2 on room air does not exclude PE.

Cardiovascular: Assess JVP, palpate apex, auscultate for murmurs (new AR suggests dissection), pericardial rub (myopericarditis), assess bilateral radial pulses simultaneously for radio-radial delay or differential volume.

• Respiratory: Reduced breath sounds and hyperresonance suggest pneumothorax.
• Pleural rub suggests pleurisy.
• Dullness to percussion with reduced air entry suggests effusion.
• Chest wall: Systematic palpation of sternum, costochondral junctions, and intercostal spaces.
• Reproducible tenderness supports MSK diagnosis but does not exclude concurrent serious pathology.

Marfanoid features: Arm span exceeding height, pectus deformity, arachnodactyly, lens dislocation, high arched palate warrant consideration of connective tissue disorder.

Investigations

ECG

• 12-lead ECG is mandatory for all chest pain presentations.
• Young patients may have normal variants including early repolarisation (J-point elevation, particularly in inferolateral leads, common in athletes and males of African descent) and juvenile T-wave pattern (persistent precordial T-wave inversion V1-V3).
• Myocarditis/pericarditis: Diffuse ST elevation (concave upward) with PR depression in multiple territories.
• Reciprocal changes absent.
• TWI evolves over days.
• PE: Most commonly sinus tachycardia.
• Classic S1Q3T3 pattern is insensitive.
• Right heart strain pattern (TWI V1-V4, RBBB) suggests massive PE.

SCAD: Regional ST elevation or depression typical of ACS, but distribution may be atypical.

D-dimer and Pulmonary Embolism Assessment

• The Wells score for PE (2-level scoring) stratifies patients into PE unlikely (score ≤4) versus PE likely (score >4).
• Components include clinical signs of DVT (3 points), alternative diagnosis less likely than PE (3 points), heart rate >100 (1.5 points), immobilisation/surgery in previous 4 weeks (1.5 points), previous DVT/PE (1.5 points), haemoptysis (1 point), malignancy (1 point).
• PERC rule (Pulmonary Embolism Rule-out Criteria) can safely exclude PE without D-dimer testing in low-risk patients when all 8 criteria are negative: age <50 years, pulse <100, SpO2 ≥95%, no haemoptysis, no oestrogen use, no prior VTE, no unilateral leg swelling, no recent surgery/trauma requiring hospitalisation.
• All 8 must be negative to apply PERC. Clinical Pearl: PERC is designed to reduce unnecessary D-dimer testing in low-risk young patients, particularly given D-dimer false positive rates of 30-40% in this demographic.
• D-dimer interpretation: Age-adjusted D-dimer (age × 10 mcg/L for patients >50 years) increases specificity.
• In young patients with Wells score ≤4, negative D-dimer (<500 mcg/L standard threshold) reliably excludes PE with negative predictive value >99.5%.
• However, D-dimer is elevated in pregnancy, recent surgery, malignancy, infection, and inflammatory conditions, limiting specificity.
• If Wells >4 or Wells ≤4 with positive D-dimer, proceed to CTPA (CT pulmonary angiogram).
• Australian Medicare (MBS item 57360) rebates CTPA with strict clinical indication requirements.

Chest X-ray

• CXR is appropriate for suspected pneumothorax, pneumonia, or pleural disease.
• Expiratory films do not improve pneumothorax detection sensitivity. Erect CXR detects pneumothoraces >2cm reliably, but smaller apical pneumothoraces may require CT if clinical suspicion is high and initial CXR equivocal.
• CXR findings in PE are usually non-specific (atelectasis, small effusion) or normal.
• Wedge-shaped peripheral opacity (Hampton hump) and oligaemia (Westermark sign) are rare.

Troponin

• High-sensitivity troponin has excellent sensitivity for myocardial injury but poor specificity in young patients.
• Causes of troponin elevation beyond ACS include myocarditis, PE (right heart strain), sepsis, renal impairment, and strenuous exercise.
• Serial troponins at 0 and 3 hours, interpreted with validated risk scores (HEART, EDACS), stratify ACS risk. The HEART score is recommended by ACEM for ED use: History, ECG, Age, Risk factors, Troponin.
• Scores 0-3 are low risk (<2% MACE at 6 weeks).

Echocardiography

• Transthoracic echo is indicated for suspected myocarditis (regional wall motion abnormality, reduced ejection fraction), pericardial effusion, or structural abnormality.
• In PE, echo may show right ventricular dilatation and dysfunction suggesting massive PE.

CT Aortogram

• Indicated for suspected aortic dissection.
• In young patients, consider connective tissue screening if dissection confirmed without clear precipitant.

Conservative Imaging Philosophy

• The Choosing Wisely Australia campaign (RACP, ACEM contributors) emphasises avoiding CT in young low-risk chest pain patients when clinical assessment and basic investigations are reassuring.
• Single CTPA delivers effective radiation dose 15-30 mSv (equivalent to 750-1500 CXRs), with breast tissue particularly radiosensitive in young women.
• Cumulative radiation exposure from multiple ED presentations contributes to lifetime cancer risk.
• Low-risk young patients (PERC negative, Wells ≤4, reassuring ECG and examination, musculoskeletal or anxiety features) do not require CTPA.
• Shared decision-making discussions should include radiation risks, false-positive rates, and incidental findings requiring follow-up.

Management

Musculoskeletal Chest Pain

• Simple analgesia (paracetamol, NSAIDs if no contraindications) and reassurance.
• Return precautions for worsening symptoms.
• No specific follow-up required for typical costochondritis.

Gastro-oesophageal Reflux Disease

Lifestyle modification (avoid late meals, elevate head of bed, reduce caffeine/alcohol), trial of proton pump inhibitor (omeprazole 20 mg daily, PBS-listed), referral to GP for ongoing management if symptoms persist beyond 4 weeks.

Anxiety/Panic Disorder

• Acute management: calm reassurance, breathing exercises to reduce hyperventilation.
• Benzodiazepines (diazepam 5 mg oral) may be appropriate for severe acute panic but should not be routine given dependence risk.
• Discharge with GP follow-up for cognitive behavioural therapy referral (Medicare-funded through Better Access scheme, MBS items 2721-2727 for clinical psychologist sessions).
• RACGP guidelines recommend CBT as first-line for panic disorder.

Pulmonary Embolism

• Anticoagulation with low molecular weight heparin (enoxaparin 1.5 mg/kg subcutaneous daily or 1 mg/kg BD) commenced in ED if high clinical suspicion pending CTPA, or immediately after PE confirmation.
• Direct oral anticoagulants (apixaban, rivaroxaban) increasingly used as first-line. eTG Complete provides detailed dosing.
• Massive PE with haemodynamic compromise requires thrombolysis (alteplase) or mechanical thrombectomy.
• Arrange thrombophilia screening (after anticoagulation course completed) for unprovoked PE in young patients.

Pneumothorax

• Primary spontaneous pneumothorax <2 cm rim on CXR in asymptomatic patient can be managed conservatively with observation and repeat CXR in 4-6 hours.
• Larger pneumothoraces require aspiration or intercostal catheter insertion.
• British Thoracic Society guidelines (adopted by Thoracic Society of Australia and New Zealand) recommend conservative initial approach where appropriate.

Myocarditis/Pericarditis

• Admission for monitoring, serial troponins, echocardiography.
• NSAIDs (ibuprofen 600 mg TDS) and colchicine (0.5 mg BD) for pericarditis.
• Exercise restriction for 3-6 months.
• Cardiology follow-up essential.
• Post-vaccination myocarditis typically mild with excellent prognosis; management is supportive.

Spontaneous Coronary Artery Dissection

• Requires urgent cardiology involvement.
• Conservative management preferred over PCI when feasible (antiplatelet, beta-blocker, ACE inhibitor) as PCI risks extension of dissection.

Red Flags

Red Flag: Tearing chest or back pain with hypotension suggests aortic dissection; activate major trauma or vascular surgery immediately.

Red Flag: Unilateral leg swelling with pleuritic chest pain and dyspnoea constitutes high-risk PE until proven otherwise; commence anticoagulation before imaging if haemodynamically stable.

Red Flag: Chest pain with syncope suggests arrhythmia, PE, or structural cardiac disease; requires admission and cardiac monitoring.

Red Flag: Known Marfan syndrome or other connective tissue disorder with any acute chest pain warrants aortic imaging.

Red Flag: Recent viral illness with chest pain, dyspnoea, and palpitations suggests myocarditis; check troponin and ECG, consider admission for monitoring.

New-onset chest pain during or immediately following vigorous exercise in previously asymptomatic young athlete requires comprehensive cardiac evaluation including stress testing or cardiac MRI to exclude structural abnormality.

• Chest pain with fever and pleuritic features may represent pneumonia with pleural involvement; CXR mandatory.
• Immunocompromised patients (HIV, immunosuppression) require broader infectious differential including fungal and mycobacterial causes.

Australian Context

Health System Navigation

• Young patients often present to ED after-hours when GP access is limited.
• Healthdirect (1800 022 222) provides 24/7 nurse triage Australia-wide and can guide appropriate service use.
• Some states operate specific youth health services (Headspace centres across Australia for ages 12-25 years, Youth Health Services in metropolitan areas) though these typically operate business hours.
• Medicare rebates for GP consultations (MBS item 23 for standard, item 36 for longer) enable follow-up without cost barrier for most young Australians.
• Mental Health Care Plans (MBS item 2700) allow access to subsidised psychology (up to 10 sessions annually under Better Access).

Rural and Remote Considerations

• Young patients in rural Australia face specific challenges including limited access to specialist services and advanced imaging.
• Royal Flying Doctor Service provides retrieval for critical cases (suspected dissection, massive PE, STEMI).
• Many rural hospitals lack on-site CT; suspected PE may require either clinical treatment without imaging or retrieval to regional centre for CTPA.
• The Victorian NURSE-ON-CALL (1300 60 60 24) and Queensland 13 HEALTH (13 43 25 84) provide telephone assessment to reduce unnecessary ED presentations.

Cultural Considerations

• Aboriginal and Torres Strait Islander peoples experience higher cardiovascular risk at younger ages due to complex interplay of social determinants, higher smoking rates, and chronic rheumatic heart disease in some communities.
• NACCHO-affiliated Aboriginal Community Controlled Health Organisations provide culturally safe primary care.
• Consider rheumatic heart disease in young Indigenous patients with chest pain and murmur, particularly from northern Australia.

Medication Access

• PBS listing ensures affordable access to essential medications.
• Anticoagulants for PE (enoxaparin, apixaban, rivaroxaban) are PBS-listed for confirmed VTE.
• PPI therapy for GORD is PBS-listed with authority required for ongoing use beyond initial scripts.
• Colchicine for pericarditis is PBS-listed under specific indications.

Radiation Safety Regulations

• Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) regulates medical radiation exposure.
• Radiologists must justify all CT examinations.
• The Image Gently and Image Wisely campaigns promoted by Royal Australian and New Zealand College of Radiologists emphasise minimising radiation in young patients.

Key Points

High-Yield: Young patients (<40 years) with chest pain have substantially lower pre-test probability for acute coronary syndrome compared to older adults, but specific cardiac causes (myocarditis, SCAD, dissection in connective tissue disorders, anomalous coronaries) must be considered based on clinical context.

• High-Yield: Apply Wells score for PE risk stratification; PERC rule can safely exclude PE in very low-risk young patients without D-dimer testing.
• D-dimer interpretation requires clinical context as false positives are common in young adults.

Costochondritis and anxiety represent the majority of chest pain presentations in young adults attending Australian EDs, but diagnosis requires systematic exclusion of serious pathology through history, examination, ECG, and selective use of investigations.

• Conservative imaging approaches in young low-risk patients reduce cumulative radiation exposure, healthcare costs, and cascade of investigations from incidental findings.
• Shared decision-making discussions should address risks and benefits of CTPA in context of individual patient risk stratification.
• Myocarditis and pericarditis, including post-vaccination cases, typically present with pleuritic chest pain, troponin elevation, and diffuse ECG changes.
• Most cases are self-limiting but require initial monitoring and exercise restriction.

Primary spontaneous pneumothorax occurs in tall thin males aged 20-30 years, often at rest; small pneumothoraces (<2 cm) can be managed conservatively with observation in asymptomatic patients.

SCAD predominantly affects young and middle-aged women, often peripartum, and accounts for significant proportion of MI in women under 50 years; conservative management preferred over PCI where feasible.

Marfan syndrome and other connective tissue disorders dramatically increase risk of aortic dissection in young patients; any acute chest pain in these patients warrants urgent aortic imaging with CT aortogram.